arduity vs trials and tribulations

arduity

noun
  • The state or quality of being arduous; steepness, difficulty. 

trials and tribulations

noun
  • Unpleasant experiences that put one's endurance and strength to the test. 

  • Everyday events that would be tiresome or redundant to recount. 

How often have the words arduity and trials and tribulations occurred in a corpus of books? (source: Google Ngram Viewer )